﻿using System;
using System.Text;
using System.Security.Cryptography;
using System.IO;

namespace weiqijiance
{
   public class Class_DES
    {

         private static string DesKey8 = "gzwk2006";
      //默认密钥向量
      private static byte[] IV64 = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };
  
  
      public  string EnDES(string encryptString)//加密
      {
         return EnDES(encryptString, DesKey8);
      }
     public  string DeDES(string decryptString)//解密
     {
         return decryptString;
     }
     /// <summary>
     /// DES加密字符串
     /// </summary>
     /// <param name="encryptString">待加密的字符串</param>
     /// <param name="encryptKey">加密密钥,要求为8B</param>
     /// <returns>加密成功返回加密后的字符串，失败返回源串</returns>
     public  string EnDES(string encryptString, string encryptKey)
     {
         try
         {
             byte[] rgbKey = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 8));
             byte[] rgbIV = IV64;
             byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);
             DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();
             MemoryStream mStream = new MemoryStream();
             CryptoStream cStream = new CryptoStream(mStream, dCSP.CreateEncryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
             cStream.Write(inputByteArray, 0, inputByteArray.Length);
             cStream.FlushFinalBlock();
             return Convert.ToBase64String(mStream.ToArray());
         }
         catch
         {
             return encryptString;
         }
    }
 
     /// <summary>
     /// DES解密字符串
     /// </summary>
     /// <param name="decryptString">待解密的字符串</param>
     /// <param name="decryptKey">解密密钥,要求为8B,和加密密钥相同</param>
     /// <returns>解密成功返回解密后的字符串，失败返源串</returns>
     public  string DeDES(string decryptString, string decryptKey)
     {
         try
         {
             byte[] rgbKey = Encoding.UTF8.GetBytes(decryptKey);
             byte[] rgbIV = IV64;
             byte[] inputByteArray = Convert.FromBase64String(decryptString);
             DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider();
             MemoryStream mStream = new MemoryStream();
             CryptoStream cStream = new CryptoStream(mStream, DCSP.CreateDecryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
             cStream.Write(inputByteArray, 0, inputByteArray.Length);
             cStream.FlushFinalBlock();
             return Encoding.UTF8.GetString(mStream.ToArray());
         }
         catch
         {
             return decryptString;
         }
     }

    }
}


